In the past a number of inventors have sought to provide machines that automatically detect blood pressure and automatically indicate and/or record the detected measurements in such manner that a physician or other trained observer can rapidly determine the systolic and diastolic pressures at a glance from the recording and can easily distinguish the valid pressure markings from artifacts. The prior art has also sought to provide machines that periodically take a series of such measurements at spaced time intervals in an automatic manner and record such measurements in a comparatively disposed arrangement such that an observer can quickly determine changes in the condition of the patient from the different measurements. Such continuing record data is particularly desirable for use in hospital operating rooms and in intensive care units at hospitals.
In an earlier patent of the present inventor, U.S. Pat. No. 3,146,777 a machine of this general type is provided in which each blood pressure measurement is graphically recorded as a series of single valued spaced dashes along a line; and with a plurality of such time spaced measurements being recorded in substantially parallel lines disposed transversely along a moving record. This recording enables a physician to very rapidly distinguish changes in the condition of the patient.